Binocular rivalry is a phenomenon created by presenting similar but different images for both eyes simultaneously. Many previous studies have investigated various brain responses to binocular rivalry. However, a response of the perceptual transition in binocular rivalry has not been clear yet. The present study aimed to measure the response of the perceptual transition in binocular rivalry using a motion rivalry stimuli with various motion angles. It is known that the perception of motion rivalry stimuli has two conditions depending on the angle between two motion directions. One is a rivalrous condition that cause binocular rivalry and the perceptual transition, and the other is a fused condition that does not cause them. Visual evoked fields (VEFs) were recorded with five healthy subjects using a 440-channel whole-head magnetoencephalogram (MEG) system. We classified trials to rivalrous or fused conditions, and calculated time averages of root mean square (RMS) values for every 100 ms in each condition. As a result, the time average of RMS values of the rivalrous condition were significantly larger than those of the fused condition after 400 ms post-stimulus. These results suggested that the perceptual transition in binocular rivalry increased the late MEG component.
Recently, lifestyle diseases (diabetics, hyperlipemia etc.) have been steadily increasing, because change of diet, lack of exercise, increase an alcoholic intake, and increase a stress. It is a matter of vital importance to us. About tens of millions of people in Japan have approached the danger of lifestyle diseases. So they have to do a blood test to make sure that they have controlled physical condition themselves. Therefore, they have to measure blood components again and again. So, they are burden too heavy. This paper describes a new noninvasive measurement of blood components based on optical sensing. This uses Fourier transform infrared spectroscopy of attenuated total reflection. In order to study, the influence of individual difference, the internal standard method was introduced. This paper describes the detail of the internal standard method and its effect to the blood components calibration. Significant improvement was obtained by using the internal standard.
Hydrogen flame was visualized by imaging at 309 nm, which coincides with the principal peak in the emission spectrum of the OH radical. An image intensifier was used to amplify the image. The background image at 337 nm was obtained simultaneously, and the spatial region corresponding to the flame image was extracted. A combination of (1) binary digitization using a threshold level and (2) Gaussian blur was used to remove the spurious spots which resulted from the grainy images obtained by the image intensifier. The use of differential imaging allowed imaging of hydrogen flame in outdoor, daylight conditions, up to a distance of 30 m.
Tsushima Warm Current is running at Japan Sea form South to North. We observed its current direction and speed at the north region of Noto peninsula by the shipboard ADCP. The observations were acted at two times, which are summer season of 2004 and 2005. From these observations, the main flows of the currents are steady, which directions are almost along to the coast and the speeds are almost 50-80cm/s. Also, at the shadow area of the peninsula for the main flow, the disturbed flows are observed.
Today, by spreading a digital camera and a cellular phone with a camera, it has been easy to capture color images. But as the capturing condition is not always enough, the contrast of an image may not be good. This paper proposes a method to improve the contrast of a color image based on the distribution of edge strength of brightness included in an objective image. Output brightness of every pixel is determined according to a Look-up-table generated by using a histogram to represent a distribution of edge strength. Saturation of color is also converted according to the HIS color relation space. The experimental results show that the output color image by the proposed method had good and natural visual contrast compared with the conventional methods.
This paper investigates an application of additive control gain to the guaranteed cost control problem of decentralized robust control for a class of discrete-time uncertain large-scale systems. Based on Linear Matrix Inequality (LMI) design approach, a class of decentralized local fixed state feedback controllers with the additive control gain is established. The novel contribution of this paper is that the multi objective control is attained by using the additive control gain. Although the additive control gain is included in the uncertain large-scale systems, the closed-loop system is asymptotically stable. In order to demonstrate the efficiency of our proposed controller, using the fuzzy logic control as the additive control gain, the simple numerical example is given.
The problem of adaptive robust state observer design is considered for a class of nonlinear dynamical systems with significant uncertainties. It is supposed that the upper bound of the nonlinearity and uncertainty is a linear function of some parameters which are still assumed to be unknown. An improved adaptation law with σ-modification is employed to estimate the unknown parameters. Then, by making use of the updated values of these unknown parameters a class of adaptive robust state observers is proposed for uncertain dynamical systems. It is also shown that by employing the proposed adaptive robust state observer, the observation error between the observer state estimate and the true state can converge asymptotically to zero in the presence of significant uncertainties. Finally, a numerical example is given to demonstrate the validity of the results.
An application of the loop transfer recovery (LTR) technique to critical control systems design is proposed for non-minimum phase plants. The controller structure is chosen as the Davison type integral controller with the Kalman filter. First, a critical control system is designed on the assumption that the state of the minimum phase part of the plant can be used for the feedback. A quadratic performance index with tuning parameters is used for determining the partial state feedback gain matrix. Second, the Kalman filter gain matrix is determined such that the output feedback controller performs as in the partial state feedback controller. The formal partial loop recovery procedure using the Riccati equation is adopted for this purpose. The proposed design method requires much simpler numerical search than the conventional one-step approach. An illustrative design example is presented.
Error in a position measurement system for a microrobot is described. The system consists of position sensitive detectors and moving landmarks, which are lasers on linear stages. The system requires the accurate positioning of the linear stages. The position measurement accuracy is investigated by changing the angle formed by the linear stages. In our experimental conditions, the maximum measurement error is about 0.2 mm, which is reduced to 5 μm by using the least square method.
In this paper, the application of receding horizon control to a two-link direct drive robot arm is demonstrated. Instead of the terminal constraints, a terminal cost on receding horizon control is used to guarantee the stability, because of the computational demand. The key idea of this paper is to apply the receding horizon control with the terminal cost which is derived from the energy function of the robot system. The energy function is given as the control Lyapunov function by considering the inverse optimality. In the experimental results, the stability and the performance are compared with respect to the horizon length by applying the receding horizon control and the inverse optimal control to the robot arm.
In a scheduling problem with worker allocation (SPWA) proposed by Iima et al, the worker's skill level to each machine is all the same. However, each worker has a different skill level for each machine in the real world. For that reason, we propose a new model of SPWA in which a worker has the different skill level to each machine. To solve the problem, we propose a new GA for SPWA consisting of the following new three procedures, shortening of idle time, modifying infeasible solution to feasible solution, and a new selection method for GA. The effectiveness of the proposed algorithm is clarified by numerical experiments using benchmark problems for job-shop scheduling.
Researches on action control of autonomous agents and multiple agents have attracted increasing attentions in recent years. The general method using action control of agents are neural network, genetic programming and reinforcement learning. In this study, we use neural network for action control of autonomous agents. Our method determines the structure and parameter of neural network in evolution. We proposed Flexibly Connected Neural Network (FCN) previously as a method of constructing arbitrary neural networks with optimized structures and parameters to solve unknown problems. FCN was applied to action control of an autonomous agent and showed experimentally that it is effective for perceptual aliasing problems. All of the experiments of FCN, however, are in only grid space. In this paper, we propose a new method based on FCN which can decide correct action in real and continuous valued space. The proposed method which called Real valued FCN (RFCN) optimizes input-output functions of each units, parameters of the input-output functions and speed of each units. In order to examine the effectiveness, we applied the proposed method to action control of an autonomous agent to solve continuous valued maze problems.
The actual sound environment system exhibits various types of linear and non-linear characteristics, and it often contains an unknown structure. Furthermore, the observations in the sound environment often contain fuzziness due to several causes. In this paper, a method for estimating the specific signal for sound environment system with unknown structure and fuzzy observation is proposed by introducing a fuzzy theory and a system model of the conditional probability type. The effectiveness of the proposed theoretical method is confirmed by applying it to the actual problem of the sound environment.
A service robot system consisting of a cellular phone available to common users and mobile robots has been investigated and developed for the purpose of supporting such human activities as the delivering documents and goods, guiding visitors and patrolling an indoor environment. The system has the feature that is spontaneously able to recognize the robot location on it using the notion of Map-matching, by complying with the request called by a user with a cellular phone. This is possible because the robot's location can be corrected with a barcode of simple structure which is detected by a slit-ray sensor on the robot and a QR-code including location information to be read by a cellular phone. These codes also have the features that are simple to install them in the environment and easy to operate because users don't use an exclusive controller like keyboard on computers, but their own accustomed cellular phone for calling the robot. From the repeated experiments performed with the robot in an indoor corridor, the proposed system was successfully evaluated in the measurement accuracy for some self-positions of the robot called and the reliability for practical navigation. In addition, when the robot was called at a certain location, its behaviors to unexpected action of the user and the effect affected on it are discussed.
Optimization methods based on meta-heuristics are proposed as a class of global optimization methods, by which the global minimum can be obtained without trapping in local minima. Particle swarm optimization(PSO), which is one of those methods, is known for its high search ability and easy implement. However, it might be difficult to find the global optimum for optimization problems which have a lot of decision variables and local optima. In this paper, we propose three types of new PSO to clear the weak point. One is a model with the nonlinear dissipative term intoroduced by Fujita, Yasuda and Yokoyama(4) to prohibit the search point's velocity being zero. The others are models with the nonlinear dissipative term with the pbest or the gbest information to disturb the search around them.
This paper proposes a method for distributed combinatorial optimization which uses mobile phones as computers. In the proposed method, an ordinary computer generates solution candidates and mobile phones evaluates them by referring privacy — private information and preferences. Users therefore does not have to send their privacy to any other computers and does not have to refrain from inputting their preferences. They therefore can obtain satisfactory solution. Experimental results have showed the proposed method solved room assignment problems without sending users' privacy to a server.
In high-speed digital processing circuits of these days, in order to match the timing between two or more signals, many meander lines have come to be used. Increasing the length of the hairpin conductor causes to increase the coupling between the parallel conductors of the hairpin, and it leads to deteriorate the frequency characteristics of phase-delay time. In this paper, a broadside-coupled meander strip line with shielding conductors connected to the ground through the vias is proposed, and the improvement on the phase-delay time characteristics is investigated by means of numerical analysis.
In PLL motor speed control systems, PID-type loop filter can improve disturbance sensitivity. In this short-paper, we show that, an existing PI-type PLL/PWM motor speed controller can be supplemented with addition a difference operation including the I-counter, together with FPGA experimental result.